Added defines for initialization of empty chains.

cpukit/ChangeLog

@@ -24,6 +24,11 @@
 	Changed type of boolean variables to bool.  Use unsigned integer type
 	for radix and width parameters.
 
+2009-11-30	Sebastian Huber <sebastian.huber@embedded-brains.de>
+
+	* score/include/rtems/score/chain.h, sapi/include/rtems/chain.h: Added
+	defines for initialization of empty chains. 
+
 2009-11-30	Sebastian Huber <sebastian.huber@embedded-brains.de>
 
 	* rtems/include/rtems/rtems/timer.h: Added timer server control block

cpukit/sapi/include/rtems/chain.h

@@ -43,6 +43,17 @@ typedef Chain_Node rtems_chain_node;
  */
 typedef Chain_Control rtems_chain_control;
 
+/**
+ *  @brief Chain initializer for an empty chain with designator @a name.
+ */
+#define RTEMS_CHAIN_INITIALIZER_EMPTY(name) \
+  CHAIN_INITIALIZER_EMPTY(name)
+
+/**
+ *  @brief Chain definition for an empty chain with designator @a name.
+ */
+#define RTEMS_CHAIN_DEFINE_EMPTY(name) \
+  CHAIN_DEFINE_EMPTY(name)
 
 #include <rtems/chain.inl>
 

cpukit/score/include/rtems/score/chain.h

@@ -93,6 +93,22 @@ typedef struct {
   Chain_Node *last;
 } Chain_Control;
 
+/**
+ *  @brief Chain initializer for an empty chain with designator @a name.
+ */
+#define CHAIN_INITIALIZER_EMPTY(name) \
+  { \
+    (Chain_Node *) &(name).permanent_null, \
+    NULL, \
+    (Chain_Node *) &(name) \
+  }
+
+/**
+ *  @brief Chain definition for an empty chain with designator @a name.
+ */
+#define CHAIN_DEFINE_EMPTY(name) \
+  Chain_Control name = CHAIN_INITIALIZER_EMPTY(name)
+
 /**
  *  @brief Initialize a Chain Header
  *